Removal and Decommissioning of Disused Gamma Irradiator in Minsk, Belarus

摘要

Under the scope of The Department of Energy's Office of Radiological Security (DOE ORS) Program the Belarusian company, "Isotope Technologies" (IT), in concert with assistance of "Radii" (a company based in Moscow, Russia), dismantled a disused gamma irradiator RKhM-?-20. This project required innovation, flexibility, and prior experience working with this type of irradiator. The team successfully removed the radioactive sources from the site and moved them to Ekores, a local radioactive waste facility. The gamma unit had been installed at the Minsk, Belarus Research Institute of Physical Organic Chemistry since 1971. This research institute is a part of the National Academy of Sciences of Belarus. There were 48 highly radioactive Cobalt 60 sources inside the unit. During the dismantling process it was discovered that the source retaining drum was broken. Therefore, the removal proved to be much more complicated than originally envisioned. IT and Radii were unable to remove a number of sources from the drum by means of standard removal equipment and finally needed to remove the entire unit itself along with the remaining sources. The problem was further complicated by only having a very short timeframe allowed for work implementation. This was because the unit was located near an elementary school requiring the team to complete the project prior to the end of summer school holidays. Moreover, the unit itself was not easily accessible. The project team developed a technical solution and accomplished the removal.